<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Feed.php 18951 2009-11-12 16:26:19Z alexander $
 */

/**
 * @see Zend_Feed_Reader_Extension_FeedAbstract
 */
require_once 'Zend/Feed/Reader/Extension/FeedAbstract.php';

require_once 'Zend/Date.php';

/**
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Reader_Extension_Syndication_Feed
extends Zend_Feed_Reader_Extension_FeedAbstract
{
	/**
	 * Get update period
	 * @return string
	 */
	public function getUpdatePeriod()
	{
		$name = 'updatePeriod';
		$period = $this->_getData($name);

		if ($period === null) {
			$this->_data[$name] = 'daily';
			return 'daily'; //Default specified by spec
		}

		switch ($period)
		{
			case 'hourly':
			case 'daily':
			case 'weekly':
			case 'yearly':
				return $period;
			default:
				throw new Zend_Feed_Exception("Feed specified invalid update period: '$period'."
				.  " Must be one of hourly, daily, weekly or yearly"
				);
		}
	}

	/**
	 * Get update frequency
	 * @return int
	 */
	public function getUpdateFrequency()
	{
		$name = 'updateFrequency';
		$freq = $this->_getData($name, 'number');

		if (!$freq || $freq < 1) {
			$this->_data[$name] = 1;
			return 1;
		}

		return $freq;
	}

	/**
	 * Get update frequency as ticks
	 * @return int
	 */
	public function getUpdateFrequencyAsTicks()
	{
		$name = 'updateFrequency';
		$freq = $this->_getData($name, 'number');

		if (!$freq || $freq < 1) {
			$this->_data[$name] = 1;
			$freq = 1;
		}

		$period = $this->getUpdatePeriod();
		$ticks = 1;

		switch ($period)
		{
			//intentional fall through
			case 'yearly':
				$ticks *= 52; //TODO: fix generalisation, how?
			case 'weekly':
				$ticks *= 7;
			case 'daily':
				$ticks *= 24;
			case 'hourly':
				$ticks *= 3600;
				break;
			default: //Never arrive here, exception thrown in getPeriod()
				break;
		}

		return $ticks / $freq;
	}

	/**
	 * Get update base
	 *
	 * @return Zend_Date|null
	 */
	public function getUpdateBase()
	{
		$updateBase = $this->_getData('updateBase');
		$date = null;
		if ($updateBase) {
			$date = new Zend_Date;
			$date->set($updateBase, Zend_Date::W3C);
		}
		return $date;
	}

	/**
	 * Get the entry data specified by name
	 *
	 * @param string $name
	 * @param string $type
	 * @return mixed|null
	 */
	private function _getData($name, $type = 'string')
	{
		if (array_key_exists($name, $this->_data)) {
			return $this->_data[$name];
		}

		$data = $this->_xpath->evaluate($type . '(' . $this->getXpathPrefix() . '/syn10:' . $name . ')');

		if (!$data) {
			$data = null;
		}

		$this->_data[$name] = $data;

		return $data;
	}

	/**
	 * Register Syndication namespaces
	 *
	 * @return void
	 */
	protected function _registerNamespaces()
	{
		$this->_xpath->registerNamespace('syn10', 'http://purl.org/rss/1.0/modules/syndication/');
	}
}
